Orbicella faveolata in St. Croix, USVI
The AOML Coral Program tracks the status and trends of coral reef ecosystems of the U.S. Atlantic and Caribbean as part of the National Coral Reef Monitoring Program (NCRMP). This summary brief provides an overview of the most recent climate monitoring efforts in Puerto Rico.
Subsurface temperature Subsurface temperature recorders (STRs) were recovered and redeployed at all 6 transects, each one composed by 4 depths (Fig. 1). In total, more than 10 million temperature observations were collected from 24 instruments (Table 1)
| Location | 1m | 5m | 15m | 25m | Total |
|---|---|---|---|---|---|
| Arecibo | 105,139 | 557,457 | 298,970 | 568,609 | 1,530,175 |
| Culebra | 364,870 | 289,966 | 444,325 | 391,261 | 1,490,422 |
| Fajardo | 123,562 | 603,161 | 241,695 | 776,035 | 1,744,453 |
| Jobos Bay | 605,123 | 316,687 | 622,946 | 512,922 | 2,057,678 |
| La Parguera | 622,965 | 513,059 | 362,198 | 404,737 | 1,902,959 |
| Rincon | 453,283 | 286,086 | 270,786 | 384,289 | 1,394,444 |
## [1] "pH = 205 observatons"
## [1] "Current = 205 observatons"
## [1] "Light = 202 observatons"
NCRMP Climate fixed sentinel site monitoring: At La Parguera - 5m site, located in SW Puerto Rico, short term instruments (54h) were deployed to monitor daily fluctuations in:
Habitat persistence: Changes in bioerosion and accretion were monitored:
Figure 1: Study sites and depths in Puerto Rico.
The temperatures that marine organisms experience are a function of local oceanographic conditions and vary with depth. To monitor subsurface temperature, six transects were established around the island. Each transect consists of STRs at four depths (1, 5, 15, 25m; Fig.2). Two years of temperature measurements were retrieved and processed from the 24 sites. Temperature was measured using SeaBird Electronics Subsurface Temperature Recorders (STR)s that collected data at 5-minute intervals. The COVID - 19 pandemic delayed collection in 2020 and local contractors were hired to swap the instruments as travel was not allowed. Some gaps exist in the data as not all instruments survived the extended deployment time. The entire record from 2017 to 2023 is shown to aid with comparison.
Figure 2: Temperature conditions at six locations in Puerto Rico (Rincon, Arecibo, Jobos Bay, La Parguera, Culebra, Fajardo) representing a depth gradient (1m, 5m, 15m and 25m). Data were collected from June 2017 to July 2023 However, the COVID 19 pandemic caused a significant delay in collection of these instruments. Contractors were hired to complete the work in 2021 as travel was not allowed. Some instruments survived the entire deployment but others have not.
Mean temperature values were similar among the locations and depths. The lowest temperatures generally occurred in February (mean: 26.5\(^\circ\)C, min: 24.7\(^\circ\)C, max: 28.5\(^\circ\)C) and the highest temperatures in September (mean: 29.4\(^\circ\)C, min: 25.4\(^\circ\)C, max: 32.2\(^\circ\)C).
Seawater carbonate chemistry can fluctuate diurnally, due to biological forcing processes such as photosynthesis andrespiration, as well as calcification and dissolution. Tocharacterize this, discrete water samples (Fig. 3) were collected at three-hour intervals (n=15) using SubsurfaceAutomatic Samplers (SAS, www.coral.noaa.gov/accrete/sas).
These samples will be analyzed for Total Alkalinity (TA), Dissolved Inorganic Carbon (DIC), and SpectrophotometricpH (SpecpH), which will be used to calculate pCO2 and aragonite saturation state (ΩAragonite). A suite of instrumentswas deployed for a 54-hour period at the La Parguera 5m site. A SeaFET was used to log pH, an EcoPAR measured Photosynthetically Active Radiation (PAR), and a Lowell Tiltmeter measured current speed and direction. Each collected measurements at 15-minute intervals (Fig. 2).
Figure 3: Data from La Parguera diurnal suite monitoring from May 21st to May 23rd. Top panel: pH and temperature fromSeaFET. Bottom panel: Photosynthetically Available Radiation (PAR) and current speed from EcoPAR and Tiltmeter. Shading denotes nighttime throughout sequence of the plot. Instruments measured parameters every 15 minutes.
Figure 4: Submered Automated Samplers (SAS) deployed to collect water samples every 3 hours
Carbonate budget assessments use transect-based surveys to quantify the abundance of carbonate producers (e.g., Corals and Crustose coralline algae), and carbonate bioeroders, (e.g., parrotfish and sea urchins). Abundances are multiplied by taxon-specific rates of carbonate alteration to determine if a reef is in a state of net accretion (habitat growth) or net loss (habitat loss) in Fig 5. At La Parguera, six transects were surveys in 2015, 2017 and 2023 to obtain carbonate budgets. These data show stable carbonate production over the monitoring timepoints. The transect results showed positive carbonate budgets in 2015, 2017 and 2023, which implies that this site supported reef accretion over the past eight years. ADD MORE HERE MAYBE CHAT DIP IN MACRO/MICRO BIOEROSION, INCREASE OF CCA, COOL OUTLIERS?
Figure 5: Total changes in net carbonate production and separated by the functional groups contributing to either calcification or bioerosion. PF represents parrotfish.
Calcification Accretion Units (CAUs) and
Bioerosion Monitoring Units (BMUs) were used to
investigate the balance between calcification and erosion. CAUs and BMUs
were collected and redeployed for the next sampling cycle. CAUs are
processed by the NCRMP Pacific Climate group and the data will be
available within a year. BMUs will be dried and cleaned using a hydrogen
peroxide solution. These samples will be weighed and scanned using a CT
scanner and then compared to their pre-scans to quantify bioerosion.
Data will be available in a year. Please reference previous datasets for
more information. Finally, landscape mosaics are used
to quantify the benthic community, and to monitor changes in coral cover
over time. Thousands of underwater
images are digitally stitched together to create a highresolution
digital archive of the reef at the time of collection. Unfortunately,
poor visibility and seastate conditions did not allow for the mosaics to
properly build DO WE WANT TO TALK ABOUT THIS OR TAKE THE WHOLE SECTION
OUT.
Figure 6: CAU and BMU pair before retreval after being deployed for 3 years. CAUs are 2 parallel PVC plates to quantify settled accretors. BMU is mounted coral skeleton installed at the base of the metal stake and has been encrusted.
AOML’s climate monitoring is a key part of the National Coral Reef Monitoring Program of NOAA’s Coral Reef Conservation Program (CRCP), providing integrated, consistent, and comparable data across U.S. Managed coral reef ecosystems. CRCP monitoring efforts aim to:
Atlantic Climate team lead: nicole.besemer@noaa.gov
Principal Investigator: ian.enochs@noaa.gov
NCRMP Coordinator: erica.towle@noaa.gov
Coral Reef Conservation Program: http://coralreef.noaa.gov
NCRMP climate monitoring: https://www.coris.noaa.gov/monitoring/climate.html
NOAA Atlantic Oceanographic and Meteorological Laboratory: http://www.aoml.noaa.gov/
These efforts were jointly funded by NOAA’s CRCP project #743 and OAP. We would like to sincerely thank the University of Puerto Rico Mayaguez campus particularly Milton Carlo for all of the mission support we received in La Parguera. We would also like to thank our other collaborators: Staff at Jobos Bay National Marine Estuary, PR Diving Services, Taino Divers and the University of the Virgin Islands for supporting our field efforts.
Puerto Rico, 2023 Field team
AOMLs NCRMP Atlantic and Caribbean Climate Team: I. Enochs, N. Besemer, A. Palacio-Castro, G. Kolodziej, T. Gill, A.Boyd, M. Jankulak, K. Simmons, A. Webb, B. Chomitz